Benjamins
chloroprene polymerization process

ABSTRACT

CHLOROPRENE IS POLYMERIZED IN AQUEOUS EMULSION BY AN IMPROVED PROCESS INVOLVING (1) INITIATING AND CONDUCTING PART OF THE POLYMERIZATION IN ONE REACTION ZONE IN WHICH THE POLYMERIZATION IS CARRIED OUT IN A CONTINUOUS MANNER AND (2) COMPLETING THE POLYMERIZATION IN A SECOND REACTION ZONE IN WHICH THE POLYMERIZATION IS CARRIED OUT IN A BATCHWISE MANNER. THE CONTINUOUS ZONE CONSISTS OF AT LEAST TWO AGITATED, CONFINED, INTERCONNECTED REACTION VESSELS AND THE BATCH ZONE CONSISTS OF AT LEAST AN EQUAL NUMBER OF SIMILARLY DEFINED VESSELS HAVING VOLUMES APPROXIMATELY EQUAL TO THOSE OF THE CONTINOUS ZONE. ADVANTAGES OF THE IMPROVED PROCESS RELATIVE TO A COM-   PLETELY CONTINUOUS PROCESS ARE INCREASED PRODUCTIVE CAPACITY, BETTER CONTROL OF THE POLYMER VISCOSITY, AND GREATER ACCESS TO THE POLYMERIZATION EQUIPMENT FOR PURPOSES OF CLEANING. RELATIVE TO A COMPLETELY BATCH PROCESS THE IMPROVED PROCESS HAS THE ADVANTAGE OF PERMITTING MORE ACCURATE CONTROL OF CONVERSION OF MONOMER TO POLYMER.

DENSWE PUlQAllUN UNITED STATES PATENT OFFICE Published at the request ofthe applicant or owner in accordance with the Notice of Dec. 16, 1969,869 O.G. 687. The abstracts of Defensive Publication applications areidentified by distinctly numbered series and are arrangedchronologically. The heading of each abstract indicates the number ofpages of specification, including claims and sheets of drawingscontained in the application as originally filed. The files of theseapplications are available to the public for inspection and reproductionmay be purchased for 30 cents a sheet.

Defensive Publication applications have not been examined as to themerits of alleged invention. The Patent Oifice makes no assertion as tothe novelty of the disclosed subject matter.

PUBLISHED JULY 25, 1972 1900,0213 CHLOROPRENE POLYMERIZATION PRUCESSEdwin Benjamins, Montague, Mich, assignor to E. I. du Pont de Nemoursand Company, Wilmington, Del. Filed May 25, 1971, Ser. No. 146,728 Int.Cl. (108d 1/09, 3/14 US. Cl. 260-92.? 1 Sheet Drawing. 14 PagesSpecification 4 3 2, ,l 5 G B l 4 Q 2 I 5 G 7 9 I Chloroprene ispolymerized in aqueous emulsion by an improved process involving (1)initiating and conducting part of the polymerization in one reactionzone in which the polymerization is carried out in a continuous mannerand (2) completing the polymerization in a second reaction zone in whichthe polymerization is carried out in a batchwise manner. The continuouszone consists of at least two agitated, confined, interconnectedreaction vessels and the batch zone consists of at least an equal numberof similarly defined vessels having volumes approximately equal to thoseof the continuous zone. Advantages of the improved process relative to acompletely continuous process are increased productive capacity, bettercontrol of the polymer viscosity, and greater access to thepolymerization equipment for purposes of cleaning. Relative to acompletely batch process the improved process has the advantage ofpermitting more accurate control of conversion of monomer to polymer.

July 25, 1972 T900,23 E. BENJAMINS CHLOROPRENE POLYMERIZATION PROCESSFiled May 25, 1971 INVENTOR EDWIN BENJAMINS ATTORNEY

